(1) Field of the Invention
The disclosure relates to introducing a pattern onto the surface of elastomeric fabric supported gloves made from conventional sulphur vulcanised formulations in the wet gel state using an engraved moulding plate, and a flat former using compression moulding technique. The pattern so produced is permanent, uniform throughout the whole of the patterned area, and may be of any design—single pattern or multi pattern. The pattern so formed also provides the glove with enhanced grip as a consequence of the uniformity of the pattern.
(2) Description of Related Art
Conventional methodology for making patterns on supported gloves rely on the following techniques: screen printing elastomer-pattern is provided from pattern on screen; use of a solvent/solvent mixture to provide a pattern to the dipped glove during the production process; laminating with the aid of an adhesive pre-embossed piece of elastomer film onto a supported glove; laminating a liner onto a glove which has been previously dipped onto a former containing a patterned surface using an adhesive; and/or laminating a glove onto a liner dressed onto a former using an adhesive
WO 2000/019847 describes a method of producing grip-enhanced gloves by way of a mould that has convex patterns on it so that when a glove is manufactured using a dipped process, the glove contains concave indentations that give a gripping effect. Practically, these gripping areas are considerably large, work well on flat surfaces only and apply only to an un-supported glove.
WO 2006/053140 describes a method of producing grip-enhanced gloves by using negatively and positively pattered moulds. In this method, gripping elements could be made very small, but due to the fact that two plates—negative and positive—are used this method cannot be used to transfer patterns to supported (using liners made of textile, aramides, etc) gloves.
U.S. Pat. No. 5,098,755 describes a means of embossing uniform patterns onto films of thermoplastic elastomers. It also refers to applications on condoms and certain other items such as surgical gloves made from thermoplastic elastomers. Thermoplastic elastomers are a special type of material composed at a molecular sub micron level of hard and soft domains. They are different from conventional elastomers. The strength of the thermoplastic material is present by virtue of the hard and soft domains. Therefore Thermoplastic materials can easily be reshaped heated (embossed) and cooled, and the embossing effect will prevail until it is heated above the softening point of the hard blocks.
U.S. Pat. No. 4,283,244 refers to making fabric lined elastomeric articles, wherein the pattern is on the outside. This process involves a methodology wherein a composite liner is dressed onto an uncured latex glove prior to oven cure and stripping the composite liner from the glove. After stripping, the glove is turned inside out and the pattern is on the outer surface.
Normally in supported glove manufacturing involving latex systems based on natural rubber latex, nitrile latex, neoprene latex, and SBR latex, embossing the pattern onto a glove during the wet gel state of the glove manufacturing operation has not been performed. Patterns are introduced to enhance grip, and in conventional technology the pattern is made by using the methodology identified in (b) above, in which the pattern is introduced to the glove by dipping into a solvent or solvent mixture prior to vulcanisation whilst still in the wet gel state. The pattern so formed is often wavy and non-uniform (i.e. the intensity of pattern varies along patterned area).
Therefore there exists a need to emboss different types of patterns and have a uniform pattern distribution in supported glove manufacturing after dipping and prior to vulcanisation. The present application provides a solution for this need.